I'm no conspiracy theorist, but why do people get so up in arms at the idea of our government shooting down 93?
FullMonte makes a pretty persuasive argument that it didn't happen, but I'd like to think that if the Air Force's only option to save untold thousands was to kill a couple hundred, they would do what needed to be done.
It's well known that the Air Force had plans in place to take down an airliner in that situation, and still do.